1. Field of the Invention
The invention herein relates to pneumatic conveyor systems. More particularly it relates to a vacuum pneumatic conveyor system for the rapid and efficient conveyance of ice.
2. Description of the Prior Art
In many commercial establishments there are ice dispensers from which patrons, employees or both can collect ice pieces (such as ice cubes) for chilling beverages or for other purposes. Among the most common examples of such establishments are the xe2x80x9cfast foodxe2x80x9d restaurants. In a typical fast food restaurant there will be a single large ice making machine in the kitchen area which manufactures large quantities of ice cubes. In the food serving area (behind the counter) and/or in the customer service area (in front of the counter) there will be at least one and usually several beverage and ice dispensing machines. Those behind the counter will be utilized by the serving staff to prepare iced beverages for window service to drive-up patrons or for counter service, while those in the customer service area will be used directly by the patrons. Commonly a patron will order and receive his or her food tray along with an empty beverage cup at the counter. The patron will then take the empty cup and food to a nearby beverage and ice dispenser, fill the cup with ice and a beverage, and then take the food and the chilled beverage to the dining area.
Such beverage and ice dispensing machines do not normally manufacture ice. Rather, each contains an internal bin which holds a limited quantity of ice cubes. The ice cubes can be dispensed from the bin by the patron""s manipulation of a lever or other control which opens a dispensing chute and allows ice to fall into the patron""s cup which is held below the discharge end of the chute. It will be readily appreciated that during busy times of the day, such as meal hours, a large number of patrons and/or service staff will be using such dispensing devices and the ice bins in the dispensers will frequently run out of ice. When this happens with a patron-area dispenser the patrons will be understandably annoyed. When it happens with a dispenser used by the serving staff, service to drive-up and counter patrons will be impeded and such patrons will become annoyed by having to wait for long periods of time to receive their beverages. To avoid this problem, such restaurants commonly assign an employee to monitor the ice and beverage dispensers and to keep the ice bins adequately full by periodically hand-carrying quantities of ice from the ice making machine in the kitchen to the dispensing machines. However, for many reasons such periodic manual refilling of the ice bins often does not get accomplished; the assigned employee may be busy at other tasks or may be forgetful, the restaurant may be especially crowded and busy, patrons may be dispensing ice in larger quantities or more rapidly than anticipated, and so forth. Whatever the cause, the failure of the restaurant to provide adequate quantities of ice upon patrons"" demand is a constant and real source of customer dissatisfaction.
Other establishments also need effective ice manufacture and distribution. Many restaurants other than fast food restaurants have salad bars, seafood bars, smorgasbords, dessert bars and the like where food must be kept chilled on beds of ice. Since the ice beds are exposed to the restaurants"" normal room temperatures, the ice rapidly melts and must be periodically replenished. Similarly, cafeterias routinely place plates of salads and desserts, containers of beverages, and similar foods on beds of ice to stay chilled until selection by patrons. Again the ice beds rapidly melt and must be replenished. The same is true of supermarkets, grocery stores, and meat and fish markets, where many fresh vegetables and especially meats and seafood are displayed on beds of ice to keep them chilled.
Outside the restaurant, grocery and food service fields, hotels and motels provide ice vending machines available to guests so that the guests can fill room ice buckets and have ice available for beverages in their own rooms. In the hotel/motel setting the vending device will be an actual ice maker, similar to the one used in a restaurant kitchen. However, since a number of such ice makers are needed to server guests throughout the facility, the overall cost is high. Therefore hotels and motels seek to minimize the number of such machines they have on the premises while yet providing a sufficient quantity of ice available to satisfy guests"" demands. However, because the number of machines is kept to a minimum, many guests find that the location of the closest ice machine is inconvenient to their rooms. Conversely, those whose rooms are close to the ice making machines frequently complain about the traffic and noise associated with other guests coming to obtain ice.
Further, ice is commonly used in hospitals for a number of purposes, including providing chilled beverages to patients and staff and filling ice packs for patient treatment. As with hotels and motels, hospitals normally use ice making machines, but again because of the cost the number of such machines is kept to a minimum consistent with patient service and care. However, because of the minimum number of machines, frequently hospital staff find that they must walk long distances to obtain ice from the closest vending machine, extending the time away from their assigned posts.
Manual transport and replenishment of ice is often unsanitary and unsafe. Such introduces the real possibility of contamination of the ice, since the person handling the ice may be ill or dirty, or the ice, while open to the ambient atmosphere may come into contact with bacteria, dirt, or other contaminants. Ice frequently spills while being transported, and if not promptly cleaned up will melt, causing dangerously slippery floors. Also, manually moving ice can cause injury to the workers, such as back injuries from lifting heavy containers of ice or injuries from falling while attempting to dump the ice into the dispensers (which are normally elevated).
In the past there have been numerous systems for pneumatically conveying ice from an ice making machine to one or more ice dispensers using xe2x80x9cpositive pressurexe2x80x9d air, i.e. air at a pressure above ambient. For instance, a convenient system which includes provision for storage of manufactured ice until needed for conveyance to the dispensers is described in U.S. Pat. No. 5,660,506 (Berge et al.). Numerous other systems are also known. Most of these systems operate at low positive pressure and high air flow volume. A few use higher pressure air at lower flow volume.
In the past vacuum systems have not been widely used as alternatives to high pressure air systems, especially in the conveyance of ice, and particularly over extended distances. A vacuum system for movement of fish from fishing boats to wharfside fish processes plants has been disclosed in U.S. Pat. No. 4,394,259 (Berry et al.). In the disclosed system, a wharf-mounted vacuum lift is used to draw fish out of the hold of a fishing boat and up to an elevated position, and then the fish drop by gravity to a belt conveyer system at the entrance to a wharfside processing plant. The total travel distance of the fish is short. Since the purpose of the system is to empty a boat""s hold as quickly as possible, so that the boat can move away from the wharf, there is no provision for metering the movement of the fish, or for moving the fish only on demand, or for directing the fish into several different routing paths. Further, the system appears to be prone to frequent blockages, since no structure is shown which would prevent an excessive number of fish from being drawn into the inlet of the vacuum line simultaneously and becoming jammed together at the inlet, thus requiring the system to be shut down so that the blockage can be removed.
Prior art systems are usually xe2x80x9cclosed pathxe2x80x9d systems, which means that somewhere in the system there is a restriction or block which prevents devices such as cleaning equipment from being run completely through the system. A few prior art systems have been capable of using liquid cleaners, but most systems have required mechanical scouring involving equipment rather than chemicals, so that the systems must be at least partially dismantled to provide access to the interiors.
The apparatus and method described and claimed as the present invention provide for a simple, economical and convenient vacuum pneumatic system for conveying ice on an as-required basis from an ice supply source (e.g., an ice maker) to one or more locations remote from that source. The system can be configured to convey the ice automatically and on various schedules or on demand to the numerous dispensing or end use locations to maintain adequate quantities of ice on hand at such locations at all times. Hand carrying or trucking of quantities of ice to fill storage, processing or dispenser bins is eliminated. By use of unique ice accumulators in the system ahead of the dispensers, the system can be operated essentially continuously, even as quantities of ice are being discharged to the dispensers.
The invention is designed to convey ice pieces to selected remote locations and keep adequate supplies of ice on hand at those locations for dispensing to restaurant patrons and employees, hotel and motel guests, hospital staff and others similarly situated. The system can be arranged with a central ice making machine in a location readily available for service but where it does not interfere with establishment operations, patrons or employees, and the ice can be readily vacuum conveyed to dispensing machines which are conveniently located for use by establishment patrons and employees. Since dispensing devices are less costly than ice making devices, an optimum number of dispensing devices can be placed at various convenient locations. The system can also be configured such that additional dispensing locations can subsequently be added or under-utilized ones can be eliminated from the system without the need to change the basic system configuration or the central ice making apparatus.
Importantly, the system can also be configured with intermediate large storage ice receptacles, from which ice can be dispensed to numerous smaller, local end use dispensers. Such intermediate receptacles further aid in permitting the system to operate generally continually at uniform ice production rates, while still providing for adequate ice availability at the end user dispensers even during periods of high ice demand.
Further, noise-generating components such as an ice making machine and the vacuum pump can be placed in their own sound proofed enclosure or room. This isolates the noise of the components from working areas, patron areas, guest areas, patient areas, etc. It also allows the ice maker or vacuum pump to work efficiently and saves on energy costs, since the heat generated by these devices can be isolated and does not add to the cooling load in adjacent working, dining, living or patient areas.
Since the system operates by vacuum rather than positive pressure, and since the accumulation chambers release ice without velocity or air noise, the delivery of ice is accomplished in a much quieter manner than has been the case with prior systems.
The present system also has the capability of being readily cleanable, which is of course very important when ice is to be conveyed. The ice conveyance conduits of the present system may, if desired, be chilled conveying lines, which results in efficient transport of the frozen items with no significant thawing in transit.
Essentially the system in its basic form receives ice from an ice source, such as a commercial ice maker which makes ice cubes, and conveys that ice under vacuum through an ice conduit from the ice source to a receptor at the remote location. The receptor may be any device which holds, reconveys and/or dispenses ice. Typical receptors include ice dispensers, ice/beverage dispensers (IBDs), accumulators, air lock devices, bins, large scale storage facilities and the like; multiple receptors in series and/or parallel are common. The source of vacuum is normally a vacuum pump in fluid communication with the ice conduit through a vacuum line. xe2x80x9cVacuumxe2x80x9d as used herein means xe2x80x9cnegative gas pressure,xe2x80x9d (i.e., gas pressure reduced below ambient pressure). The vacuum pump creates negative gas pressure within the conduit which causes the ice to be conveyed by xe2x80x9cpullingxe2x80x9d (rather than by xe2x80x9cpushingxe2x80x9d as positive pressure prior art systems have done) to the receptor.
Numerous variations and embodiments of the system are possible. These involve incorporation into the system of one or more diverters or diverter/shifters which permit the routing of ice and/or vacuum into and through multiple pathways to any of a plurality of receptors. Such diversions may include both increasing diversions, where additional paths are opened, and decreasing diversions, where multiple parts are combined.
The ice may be sent directly to receptors which themselves can dispense ice (and often also beverages) to end users, or may be sent to accumulators, which hold quantities of ice and then release them to other accumulators or ice dispensers, or may be sent to air lock devices, which permit the ice to be projected substantial distances, to permit filling of large or mobile containers.
The system may incorporate intermediate storage of ice, so that intermediate storage containers may be filled while end user ice demand is low and then be used to dispense the stored ice during high demand periods when the ice sources cannot produce new ice fast enough to keep up with the demand.
Therefore, in one apparatus embodiment, the invention involves apparatus for conveying ice in the form of a plurality of pieces each having physical characteristics amenable to transport by negative air pressure pneumatic conveyance, from a source of the ice to a remote location under the negative air pressure, which comprises a hollow elongated ice conduit connecting the source of ice and the remote location and providing ice communication therebetween; a receptor at the remote location for receiving the ice; and a vacuum pump in fluid communication through a vacuum line with the receptor for withdrawing air from the conduit and creating a vacuum comprising the negative air pressure in the conduit, the negative air pressure causing the ice to traverse the conduit from the source into the receptor.
In other apparatus embodiments, the invention involves the receptor being an ice dispensing device or ice/beverage dispensing device, single or double accumulator(s) each having therein an openable gate for release therefrom at the remote location of accumulated pieces of ice conveyed thereto from the source, or an air lock device which is connected to the ice conduit on an upstream side and which has an inlet for pressurized air from a source thereof on a downstream side and another conduit extending from the downstream side for passage of the pressurized air, such that ice entering the air lock device from the ice conduit passes through the air lock device and propelled through the another conduit at high velocity by the pressurized air.
In yet other apparatus embodiments, the invention involves sensors for detecting the presence or absence of ice in the receptor, and, when the presence of the ice is detected in the receptor, determining the quantity of ice so detected.
Partial or complete electronic control of the system is contemplated.
Sources of ice may include machinery for making pieces of ice, an ice unbridger, a container having the pieces of ice therein and from which the pieces of ice are motivated into to the ice conduit, another conduit in which the pieces of ice are being conveyed and which is in ice communication with the ice conduit or introducer means for introducing the pieces of ice essentially seriatim into the ice conduit.
In a process or method embodiment, the invention involves a process for conveying ice in the form of a plurality of pieces each having physical characteristics amenable to transport by negative air pressure pneumatic conveyance, from a source of the ice to a remote location under the negative air pressure, which comprises providing a hollow elongated ice conduit connecting the source of ice and the remote location and providing ice communication therebetween; a receptor at the remote location for receiving the ice; and a vacuum pump in fluid communication through a vacuum line with the receptor for withdrawing air from the conduit and creating a vacuum comprising the negative air pressure in the conduit, the negative air pressure causing the ice to traverse the conduit from the source into the receptor; withdrawing air from the receptor and conduit and creating a vacuum comprising the negative air pressure in the receptor and conduit; and causing the ice to traverse the conduit from the source into the receptor under the influence of the negative air pressure.
In another method or process embodiment, the invention involves connecting the vacuum line in fluid communication into the ice conduit at a first point of connection upstream of a second point of connection of the ice conduit into the receptor, and spaced apart from the second point of connection by an interval not greater than a distance that the ice pieces can traverse under momentum imparted to them by their prior conveyance through the conduit by the negative air pressure; and conveying the ice pieces under that amount of force of the negative air pressure at the first point of connection sufficient to cause the ice pieces to continue to traverse entirely through the first conduit and into the receptor without diversion of any ice pieces into the first vacuum line.
In yet another method or process embodiment, the invention involves introducing a liquid cleaner into the ice conduit, conveying the liquid cleaner through the conduit by the negative air pressure and contacting substantially all interior surfaces of the conduit for removal of contaminants therefrom, such that the interior surfaces are cleaned of the contaminants by passage of the liquid cleaner, and, optionally, also causing at least a portion of the liquid cleaner also to pass through and contact substantially all interior surfaces of at least one of the source of ice and the receptor, such that such that the interior surfaces are cleaned of the contaminants by passage of the liquid cleaner.
In other process and apparatus aspects the invention involves apparatus which operates to divert and return conveying air to the vacuum pump and permit ice to continue to travel by momentum into a receptor. The same aspect of the system can be used to remove some or all of water or other liquids from the system.
In other method or process embodiments, the invention conveying the ice through a plurality of serially connected conduits to reach a receptor, or simultaneously routing ice and vacuum through a plurality of serially connected paired ice conduits and vacuum lines to a receptor.
Also as a principal element in this invention is a unique type of diverter/air shifter, which permits diversion of both air and ice through 2-4 different routes.
These and other embodiments, aspects, applications and variations of the invention will be described below, with particular reference to the accompanying Figures of the drawings.